3D package applications such as package-on-package (PoP) are becoming increasingly popular and widely used in mobile devices because they can enhance electrical performance by integrating logic chips (e.g., application processors (APs)), high capacity/bandwidth memory chips (e.g., dynamic random access memory (DRAM), wide input/out (WIO) chips, low power double data rate X (LPDDRx) chips, and the like), and/or other heterogeneous chips (e.g., sensors, micro-electro-mechanicals (MEMs), networking devices, and the like), for instance. Existing PoP devices and packaging structures face challenges to meet fine channels and high density routing requirements of next-generation applications.